using microcontroller in Simulink

Can a microcontroller be used in simulink?
Please tell me if I can use ATmega88 microcontroller in Simulink?If yes then please guide me how to do it...

No you can't this isn't what Matlab / Simulink is used for.

The closest you could get to this to my knowledge would be to incorporate C code into the Simulink model, but really Simulink is there to build represetative models of control functions using standard blocks its not detailed a circuit simulator. So for example you could simulate a SMPS using discreet control blocks and fundamental electrical components (L,R,C, source, sink)


You can however interface Simulation with different simulation tools, for example to implement VHDL code.